Antimicrobial Nano-Agents: The Copper Age

Magnetic field-driven nanospears for enhancing antibacterial strategy

Antimicrobial resistance poses a significant challenge to global health, necessitating innovative strategies to combat bacterial infections. This study introduces a novel approach that combines the mechanical effects of magnetically-driven nanospears with photothermal action to enhance bacterial eradication efficacy. The anisotropic Fe3O4@PDA nanorobots with controllable aspect ratios are synthesized by encapsulating strong magnetic Fe3O4 nanospears with polydopamine (PDA), which exhibits high near-infrared (NIR) photothermal efficiency. Because the sharp tips on the Fe3O4@PDA nanospears concentrate mechanical stress on bacterial membranes, they exhibit enhanced antibacterial activity when a rotating magnetic field (RMF) is applied to increase the mechanical damage. Notably, the combination of RMF and NIR irradiation markedly enhance biofilm removal and bacterial inactivation, especially against Staphylococcus aureus. The aspect ratio is found to have a high influence on the coupling effect, and the ellipsoidal nanoparticles without the sharp tips exhibit a significantly reduced effect compared to the nanospears. The piercing effect of nanospears on bacterial membranes and the synergistic impact of mechanical penetration and photothermal treatment are clearly observed via experimental analysis. Finite element analysis (FEA) and coarse-grained molecular dynamics (CGMD) simulations further confirm that the nanospears can effectively penetrate bacterial membranes and the elevated temperatures amplify membrane disruption. This photothermal-magnetomechanical synergistic effect offers a promising and function-tailored strategy to address antimicrobial resistance, positioning nanospears as a viable alternative to conventional antibacterial treatments.

Revisiting the characteristics of nanomaterials, composites, hybrid and functionalized materials in medical microbiology

Unlike traditional materials designed to form large structures, many modern materials are presented in the form of powders resulting from a molecular level control of their composition and structure, making possible the miniaturization and fine-tuning of their properties to act in cellular dimensions with customized tasks. Several new materials for biomedical and microbiology applications appear every year. Although many of them are called nanomaterials, there may be a more precise description or classification. In this work, we review and detail the structural classification of nanometric, functionalized, hybrid and composite materials, mainly based on descriptions given by the International Union of Pure and Applied Chemistry (IUPAC). Besides we included smart and multifunctional materials, cassification based on performance. The second section shows how these materials are used in the area of medical microbiology, grouping these applications into barriers for microorganisms on surfaces, disinfectants in clinical practice, targeting of pathogens, detectors of microorganisms or their metabolites, and also as substrates to stabilize, transport, or nourish beneficial microorganisms. Finally, we will discuss some evidence that indicates the environmental risk and bacterial resistance alerts that should be taken into account with the use of these advanced powder materials.

Structurally Engineered SO2-Releasing Polymeric Nanoassembly for Broad-Spectrum Antibacterial Activity

Cationic antimicrobial agents are widely recognized for combating microbial infections through their membrane-disruptive properties. Recently, sulfur dioxide (SO2) gas therapy has emerged as a promising alternative for treating diseases, including bacterial infections. However, current systems often target only specific bacterial strains. Herein, we present amphiphilic alternating copolymers, DAPx (x = 1, 2, 3), incorporating cationic residues and thiol-responsive SO2-releasing moieties. In aqueous environments, DAPx copolymers self-assemble into micellar nanoassemblies (DAPxNp), exposing hydrophilic cationic residues outward and encapsulating hydrophobic SO2-releasing moieties within the core to enable controlled and sustained release of SO2 in the presence of glutathione (GSH). In vitro studies reveal excellent biocompatibility of DAP2 Np with broad-spectrum antibacterial activity against both Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. Mechanistic investigations confirm bacterial eradication via membrane disruption and reactive oxygen species generation. This study underscores the remarkable efficacy of SO2-releasing cationic polymers in resisting bacterial infections.

CuO nanoparticles facilitate soybean suppression of Fusarium root rot by regulating antioxidant enzymes, isoflavone genes, and rhizosphere microbiome

BACKGROUND

Fusarium root rot is a widespread soil-borne disease severely impacting soybean yield and quality. Compared to traditional fertilizers' biological and environmental toxicity, CuO nanoparticles (NPs) hold promise for disease control in a low dose and high efficiency manner.

METHODS

We conducted both greenhouse and field experiments, employing enzymatic assays, elemental analysis, qRT-PCR, and microbial sequencing (16S rRNA, ITS) to explore the potential of CuO NPs for sustainable controlling Fusarium-induced soybean disease.

RESULTS

Greenhouse experiments showed that foliar spraying of CuO NPs (10, 100, and 500 mg L-1) promoted soybean growth more effectively than EDTA-CuNa2 at the same dose, though 500 CuO NPs caused mild phytotoxicity. CuO NPs effectively controlled root rot, while EDTA-CuNa2 worsened the disease severity by 0.85-34.04 %. CuO NPs exhibited more substantial antimicrobial effects, inhibiting F. oxysporum mycelial growth and spore germination by 5.04-17.55 % and 10.24-14.41 %, respectively. 100 mg L-1 CuO NPs was the optimal concentration for balancing soybean growth and disease resistance. Additionally, CuO NPs boosted antioxidant enzyme activity (CAT, POD, and SOD) in leaves and roots, aiding in ROS clearance during pathogen invasion. Compared to the pathogen control, 100 mg L-1 CuO NPs upregulated the relative expression of seven isoflavone-related genes (Gm4CL, GmCHS8, GmCHR, GmCHI1a, GmIFS1, GmUGT1, and GmMYB176) by 1.18-4.51 fold, thereby enhancing soybean disease resistance in place of progesterone-receptor (PR) genes. Field trials revealed that CuO NPs' high leaf-to-root translocation modulated soybean rhizosphere microecology. Compared to the pathogen control, 100 mg L-1 CuO NPs increased nitrogen-fixing bacteria (Rhizobium, Azospirillum, Azotobacter) and restored disease-resistant bacteria (Pseudomonas, Burkholderia) and fungi (Trichoderma, Penicillium) to healthy levels. Furthermore, 100 mg L-1 CuO NPs increased beneficial bacteria (Pedosphaeraceae, Xanthobacteraceae, SCI84, etc.) and fungi (Trichoderma, Curvularia, Hypocreales, etc.), which negatively correlated with F. oxysporum, while recruiting functional microbes to enhance soybean yield.

CONCLUSION

100 mg L-1 CuO NPs effectively promoting soybean growth and providing strong resistance against root rot disease by improving antioxidant enzyme activity, regulating the relative expression of isoflavone-related genes, increasing beneficial bacteria and fungi and restoring disease-resistant. Our findings suggest that CuO NPs offer an environmentally sustainable strategy for managing soybean disease, with great potential for green production.

Chitosan hydrogels loaded with Cu3SnS4 NSs for the treatment of second-degree burn wounds

Globally, burns pose a significant health concern, impairing the skin's normal function and elevating the risk of bacterial infection. Traditional burn dressings often fail to deliver the anticipated therapeutic benefits. Hence, there is an urgent need to develop an ideal wound dressing that exhibits satisfactory antibacterial properties, biocompatibility, and the ability to expedite burn wound healing. Here, we prepared chitosan-based hydrogel (CS/GP), and then loaded copper-tin -sulfur (Cu3SnS4) synthesized by hydrothermal method into the hydrogel to construct a new hydrogel dressing (CS/GP/Cu3SnS4). In vitro antibacterial tests demonstrated that the CS/GP/Cu3SnS4 hydrogel dressing exhibits considerable antibacterial properties, achieving an antibacterial rate exceeding 95% after 4 h of contact with Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Additionally, CCK-8 and live/dead cell staining experiments confirmed the dressing's good biocompatibility. Furthermore, in vivo experiments confirmed that the CS/GP/Cu3SnS4 hydrogel dressing demonstrates superior wound healing performance compared to the control group. In conclusion, the CS/GP/Cu3SnS4 hydrogel shows potential application prospects as a burn wound dressing.

Recent Advances in Crystalline Porous Materials for Antibacterial Applications

Bacterial infections remain a significant and escalating threat to global health, exacerbated by multidrug-resistant strains that undermine the efficacy of conventional antibiotics. This pressing issue underscores the urgent need for the development of new antimicrobial materials. Among these, molecular-based crystalline porous materials, such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs), hydrogen-bonded organic frameworks (HOFs), and supramolecular assembly frameworks (SAFs), have emerged as a promising class of antibacterial agents. These materials exhibit well-defined crystallinity and tunable structures, offering exceptional versatility for antibacterial applications. Notably, their high surface area, adjustable pore size, and potential for functionalization enable efficient loading and controlled release of antibacterial agents, including metal ions and antibacterial molecules. This review provides a comprehensive analysis of recent advancements in this field, highlighting design strategies, structural diversity, antibacterial mechanisms, and applications. Finally, we discuss the current challenges and outline future opportunities for the practical development and deployment of antibacterial porous materials.

Inorganic Nanomaterials Meet the Immune System: An Intricate Balance

The immune system provides defense against foreign agents that are considered harmful for the organism. Inorganic nanomaterials can be recognized by the immune system as antigens, inducing an immune reaction dependent on the patient's immunological anamnesis and from several factors including size, shape, and the chemical nature of the nanoparticles. Furthermore, nanomaterials-driven immunomodulation might be exploited for therapeutic purposes, opening new horizons in oncology and beyond. In this scenario, we present a critical review of the state of the art regarding the preclinical evaluation of the effects of the most promising metals for biomedical applications (gold, silver, and copper) on the immune system. Because exploiting the interactions between the immune system and inorganic nanomaterials may result in a game changer for the management of (non)communicable diseases, within this review we encounter the need to summarize and organize the plethora of sometimes inconsistent information, analyzing the challenges and providing the expected perspectives. The field is still in its infancy, and our work emphasizes that a deep understanding on the influence of the features of metal nanomaterials on the immune system in both cultured cells and animal models is pivotal for the safe translation of nanotherapeutics to the clinical practice.

A Tailored Hydrogel With Local Glycemia Management, Antioxidant Activity, and Photothermal Antibacterial Properties for Diabetic Wound Healing

The management of chronic diabetic wounds is a complex challenge requiring local glycemic regulation, modulation of inflammation levels, and prevention of bacterial infections. Therefore, a multifunctional wound dressing with antioxidant, local glycocontrol, and antibacterial properties is developed to promote diabetic wound healing. This dressing is constructed by co-loading gold-cerium oxide (AuCeO2) dumbbells and glucose oxidase (GOx) into a reactive oxygen species (ROS)-sensitive hydrogel matrix (ACG gels). In this system, Au-CeO2 dumbbells effectively eliminate ROS, protecting cells from oxidative stress-induced damage while exhibiting significant near-infrared photothermal antibacterial activity. Additionally, the controlled release of GOx decreases blood glucose levels in the wound microenvironment, alleviating oxidative stress and inhibiting bacterial growth proliferation, thereby expediting the healing process. ACG gels demonstrated excellent wound healing-promoting properties in two in vivo wound models, providing a promising and effective platform for diabetic wound management.

A multiple-crosslinked injectable hydrogel for modulating tissue microenvironment and accelerating infected diabetic wound repair

Elevated oxidative stress and inflammation, bacterial infections, and vascular impairment undoubtedly impede the normal diabetic wound healing process, which has encouraged the development of high-performance dressings for wound management. Herein, a new type of multiple-crosslinked injectable hydrogel, GCP, was developed via the radical polymerization of propenyl groups and the formation of copper‒polyphenol coordination bonds and Schiff base bonds. The copper‒polyphenol coordination and Schiff base bonds in the GCP hydrogel were disrupted in the acidic microenvironment of diabetic wound, resulting in the release of copper ions and protocatechualdehyde (PA) to scavenge reactive oxygen species (ROS), promote angiogenesis and cell migration, and exert antibacterial and anti-inflammatory activities via the CuPA complexes. Consequently, markedly accelerated infected diabetic wounds healing was achieved through this tissue microenvironment remodeling strategy. Moreover, the underlying mechanism of the antibacterial properties was investigated by 16S rRNA sequencing. The results indicated that the CuPA complexes can clearly inhibit the growth and reproduction of S. aureus by downregulating specific genes associated with ABC transporters, hindering bacterial protein synthesis, and enhancing oxidoreductase activity. This innovative hydrogel platform for wound management may inspire new methods for the preparation of high-performance biomedical materials and the treatment of other clinical diseases.

Recombinant collagen microneedles for transdermal delivery of antibacterial copper-DNA nanoparticles to treat skin and soft tissue infections

Skin and soft tissue infections (SSTI) include bacterial infections of the skin, muscles, and connective tissue such as ligaments and tendons. SSTI in patients with immunocompromising diseases may lead to chronic, hard-to-heal infected wounds, resulting in disability, amputation, or even death. To treat SSTI and rebuild the defensive barrier of the skin, here we utilize recombinant type XVII collagen protein (rCol XVII) to construct biodegradable, regenerative collagen microneedles (rCol-MNs) for transdermal delivery of antibacterial agents. Spheroidal copper-DNA antibacterial nanoparticles (Cu-CpG NPs; CpG represents short single-stranded synthetic DNA molecules of cytosine and guanine) are synthesized with copper ions and CpG oligodeoxynucleotides (ODNs), followed by polydopamine (PDA) coating to obtain Cu-CpG@PDA. Doping Cu-CpG@PDA into rCol-MNs yields Cu-CpG@PDA-loaded rCol-MNs. These microneedles combine the photothermal conversion property of PDA, antibacterial properties of copper ions, innate immune activation of CpG ODNs, and skin regenerating ability of rCol XVII, allowing the treatment of SSTI and also regenerating the damaged skin. In a mouse model, we show that the Cu-CpG@PDA-loaded rCol-MNs rescue skin wound infections, facilitate the orderly deposition of collagen at the wound site, and promote the healing of infected full-thickness wounds without noticeable scar formation. rCol-MNs serve as a transdermal delivery vehicle and, simultaneously, a reservoir of skin-regenerating recombinant collagen, bringing combined benefits of infection control and skin regeneration. SIGNIFICANCE STATEMENT: Treatment of soft tissue infection requires the delivery of antibacterial agents into the soft tissue or dermis while providing a regenerating environment for open wounds. Here, we devise recombinant collagen microneedles (rCol-MNs) to meet both requirements.

Diversity of copper-containing nanoparticles and their influence on plant growth and development

Copper (Cu) is an important microelement for plants, but in high concentrations it can be toxic. Cu-containing nanoparticles (Cu NPs) are less toxic, their use for plants is safer, more effective and economical than the use of Cu salts. This review presents detailed information on the chemical diversity of Cu NPs and various methods of their synthesis. The mechanisms of the effect of Cu NPs on plants are described in detail, and examples of research in this area are given. The main effects of Cu NPs on plants are reviewed including on their growth and development (organogenesis, mitosis, accumulation of biomass), biochemical processes (intensity of photosynthesis, antioxidant status and intensity of lipid peroxidation processes), gene expression, plant resistance to abiotic and biotic stress factors. The prospects of using Cu NPs as mineral fertilizers are shown by describing their stimulation effects on seed germination, plant growth and development, and on increase of plant resistance to stress factors. The protective effect of Cu NPs is often explained by their antioxidant activity. At the same time, there are a number of studies demonstrating the negative impact of Cu NPs on plant growth, development and the intensity of photosynthesis, depending on their concentration. Cu NPs have a pronounced antibacterial effect on bacterial phytopathogens of cultivated plants, as well as on a number of phytopathogenic fungi and nematodes. Thus, Cu NPs are promising agents for agriculture, while their effect on plants requires careful selection of optimal concentrations and comprehensive studies to avoid a toxic effect.

Metal-Protein Hybrid Materials: Unlocking New Frontiers in Biomedical Applications

Metal-protein hybrid materials represent a novel class of functional materials that exhibit exceptional physicochemical properties and tunable structures, rendering them remarkable applications in diverse fields, including materials engineering, biocatalysis, biosensing, and biomedicine. The design and development of multifunctional and biocompatible metal-protein hybrid materials have been the subject of extensive research and a key aspiration for practical applications in clinical settings. This review provides a comprehensive analysis of the design strategies, intrinsic properties, and biomedical applications of these hybrid materials, with a specific emphasis on their potential in cancer therapy, drug and vaccine delivery, antibacterial treatments, and tissue regeneration. Through rational design, stable metal-protein hybrid materials can be synthesized using straightforward methods, enabling them with therapeutic, delivery, immunomodulatory, and other desired functionalities. Finally, the review outlines the existing limitations and challenges associated with metal-protein hybrid materials and evaluates their potential for clinical translation, providing insights into their practical implementation within biomedical applications.

Copper-Based Nanozymes: Potential Therapies for Infectious Wounds

Bacterial infections are a significant obstacle to the healing of acute and chronic wounds, such as diabetic ulcers and burn injuries. Traditional antibiotics are the primary treatment for bacterial infections, but they present issues such as antibiotic resistance, limited efficacy, and potential side effects. This challenge leads to the exploration of nanozymes as alternative therapeutic agents. Nanozymes are nanomaterials with enzyme-like activities. Owing to their low production costs, high stability, scalability, and multifunctionality, nanozymes have emerged as a prominent focus in antimicrobial research. Among various types of nanozymes, metal-based nanozymes offer several benefits, including broad-spectrum antimicrobial activity and robust catalytic properties. Specifically, copper-based nanozymes (CuNZs) have shown considerable potential in promoting wound healing. They exhibit strong antimicrobial effects, reduce inflammation, and enhance tissue regeneration, making them highly advantageous for use in wound care. This review describes the dual functions of CuNZs in combating infection and facilitating wound repair. Recent advancements in the design and synthesis of CuNZs, evaluating their antimicrobial efficacy, healing promotion, and biosafety both in vitro and in vivo on the basis of their core components, are critically important.

Photo-responsive Cu-tannic acid nanoparticle-mediated antibacterial film for efficient preservation of strawberries

The existing films used for fruit preservation suffer from insufficient preservation abilities. This study introduces Cu-tannic acid (Cu-TA) nanoparticles, synthesized from tannic acid (TA) and Cu2+, to enhance food packaging properties. Integrated into a chitosan-gelatin (CG) matrix, the resultant Cu-TA nanocomposite films exhibit superior antibacterial efficacy and killing rates of Escherichia coli and Staphylococcus aureus more than 99 %, and double the shelf life of strawberries, underscoring the exceptional freshness preservation capabilities of film. Additionally, the tensile strength of the Cu-TA nanocomposite films increased by 1.75 times, the DPPH radical scavenging percentage increased from 29.4 % to 68.4 %, and the water vapor permeability (WVP) decreased by about 60 % compared to the pure CG films. Comprehensive cytotoxicity and migration assessments confirm the safety of film, paving the way for their application in food packaging. The excellent performance of the Cu-TA nanocomposite films positions them as a formidable solution for protecting perishable food items.

Balancing Risks versus Benefits: Vitamin C Therapy versus Copper Oxide Nanoparticles Toxicity in Albino Rats' Submandibular Salivary Gland

OBJECTIVES

 This study aimed to examine the suppressive effect of the natural antioxidant vitamin C (VC) against submandibular gland toxicity induced by copper oxide nanoparticles (CuO-NPs).

MATERIALS AND METHODS

 Three groups of 30 mature male albino rats (4 weeks old) weighing between 150 and 200 g were selected. The rats were randomly assigned for 6 weeks to receive: intraperitoneal injection (IP) of vehicle (control group); IP of 2.5 mg/kg body weight (bw) of CuO-NPs (CuO-NPs group); and IP of 2.5 mg/kg bw of CuO-NPs, combined with a daily oral dose of 100 mg/kg bw of VC in drinking water via gavage (CuO-NPs/VC group). The rats were euthanized, and their submandibular glands were dissected for histological evaluation, including hematoxylin and eosin staining and immunohistochemistry for Ki-67 and caspase-3.

STATISTICAL ANALYSIS

 The area expression for Ki-67 and caspase-3 was statistically analyzed using GraphPad Prism. Following analysis of variance analysis, Tukey's post hoc was used for multiple comparisons. The significance level was set at p < 0.05.

RESULTS

 CuO-NPs caused significant cytotoxic effects on submandibular salivary gland cells in albino rats. This led to an increase in Ki-67 and caspase-3 levels compared with the control group. VC administration improved tissue histology and reduced Ki-67 and caspase-3 levels in the VC/CuO-NPs group compared with rats treated with CuO-NPs alone.

CONCLUSION

 The study revealed significant cytotoxic effects of CuO-NPs on the submandibular salivary gland of albino rats. VC effectively mitigated these toxic effects, suggesting its potential as a readily available antioxidant.

Liposome/chitosan coating film bioplastic packaging for Litchi fruit preservation

Chitosan is an ideal coating film for food preservation, but the performance of a single chitosan coating film is not good. Herein, the liposome was prepared by embedding copper nanoparticles (CuNPs) and thyme essential oil (TEO) in the hydrophilic and hydrophobic double-domain structure formed by phospholipids, and combining with chitosan to obtain a chitosan-based coating film for litchi preservation. The liposome was well-dispersed and stable with an average particle size of about 190 nm. The liposome showed excellent controllable release properties, and the cumulative release rate of TEO was 65.17 % and that of CuNPs was 15.17 % after 7 days. Furthermore, the oxygen and water vapor barrier properties of the coating film were greatly improved. Importantly, the film possessed effective antioxidant, antibacterial activity and excellent safety, which presents a better fresh-keeping effect on litchi. This study provides insights into the design and manufacture of food packaging for controllable and long-lasting preservation.

Copper peroxide-loaded lignin-based non-isocyanate polyurethane foam for wound repair applications

Wound healing is a complex process and the mechanism of the tissue repair process involves many complex steps: inflammation, proliferation, and maturation. Wounds can be divided into two main categories: acute and chronic wounds. Non-healing wounds usually follow a bacterial infection. Many types of materials on the market have been developed for use as wound dressings. Polyurethane foam for wound dressings has many advantages over other materials, especially for moderate wounds and drainage. In this study, lignin-based non-isocyanate polyurethane foams were prepared using a green route by oxygen alkylation modification of enzymatically dissolved lignin, cyclic carbonation and polymerization with diamines to add a blowing agent. By loading CuO2 on the surface of the prepared lignin-based non-isocyanate polyurethane foam, a pH-responsive wound dressing, named lignin-based non-isocyanate polyurethane/copper peroxide composite foam (named NIPU foam-CuO2), was prepared, which can specifically release the strong oxidizing OH under acidic conditions. The composite foam can effectively kill the bacteria in the wound. The test results proved that the composite foam has excellent mechanical properties, thermal stability, and biocompatibility. NIPU-foam-CuO2 100 mM inhibited two types of bacteria, Escherichia coli, and Staphylococcus aureus, by up to 98 % and 95 % within 8 h, respectively. It also shows excellent performance in promoting wound healing in organism experiments as well as in the subsequent histological staining. The lignin-based NIPU foams of this work exhibit remarkable innovation and unique properties in terms of environmental friendliness, performance and antimicrobial resistance. At the same time, we also mention potential problems such as drug resistance in the long-term use of NIPU-CuO2 foams.

Fabrication of Self-Standing Inorganic-Organic Composite Films at a Miscible Interface by "Soft Spray" Technique

Membranes have extensive applications in catalysis, separation, antimicrobial activities, and sensing. However, developing a simple and environmentally friendly method for preparing membranes remains challenging. Here, we report a novel strategy for fabricating self-standing inorganic-organic composite films at the miscible liquid/liquid interface using a soft spray technique. Specifically, metal salt solutions are sprayed onto the interface between an alkaline poly(vinyl alcohol) (PVA) solution to form heterogeneous metal hydroxide/PVA composite films with PVA as the supporting substrate. The preparation method is simple, easy to manipulate, environmentally friendly, and resource-efficient. It has been extended to prepare metal phosphate/PVA, metal carbonate/PVA, and metal sulfide/PVA composite films. Notably, the copper hydroxide/PVA (Cu(OH)2/PVA) composite films exhibit exceptional tensile strength (19.0 MPa) and remarkable antimicrobial properties (99.9%). This simple soft spray-assisted technique provides a novel approach for fabricating miscible interface composite films.

Adaptations of Rhodococcus rhodochrous Biofilms to Oxidative Stress Induced by Copper(II) Oxide Nanoparticles

Copper(II) oxide nanoparticles (CuO NPs) are used in different industries and agriculture, thus leading to their release to the environment, which raises concerns about their ecotoxicity and biosafety. The main toxicity mechanism of nanometals is oxidative stress as a result of the formation of reactive oxygen species caused by metal ions released from nanoparticles. Bacterial biofilms are more resistant to physical and chemical factors than are planktonic cells due to the extracellular polymeric matrix (EPM), which performs a protective function. Hydrocarbon-oxidizing bacteria of the genus Rhodococcus, well-known biodegraders of toxic organic pollutants and bioremediation agents, are capable of producing biofilms, which, as we proposed, are more resistant to metal nanoparticles, while the particular adaptation mechanisms have not yet been clarified. In this study, we study the adaptation mechanisms of Rhodococcus rhodochrous IEGM 1363 biofilms to CuO NPs in a wide range of concentrations (0.001-0.1 g/L), including morphological and ultrastructural cell alterations. The results obtained on the long-term dynamics (≤72 h) and localization of EPM structural components, in particular, lipids, polysaccharides, and proteins, indicated their important role in the complex adaptive response of alkanotrophic Rhodococcus to oxidative stress caused by copper nanooxide. The observed changes in the ultrastructure and element composition included binding of CuO nanoparticles by the cell wall to prevent their penetration inside cells and intracellular accumulation of potassium, magnesium, phosphorus, and sulfur in electron-dense inclusions, which may be associated with a metabolic stress reaction. Understanding the mechanisms of interaction between nanometals and Rhodococcus biofilms will contribute to the development of biocatalysts based on immobilized bacterial cells and bioremediation methods.

Efficient Control of Fusarium Head Blight and Reduction of Deoxynivalenol Accumulation by a Novel Nanopartner-Based Strategy

Chemical control of Fusarium head blight (FHB) in wheat plants is often challenged by the resistance outbreak and deoxynivalenol (DON) accumulation. Developing green partners for fungicides is crucial for reducing fungal growth, mycotoxin contamination, and agricultural fungicides input. Herein, we investigated the mechanism of MgO nanoparticles (NPs) in controlling FHB. The EC50 of MgO NPs on mycelial growth was 105.2 μg/mL. At this concentration, they inhibited the spore germination, DON production, and wheat colonization of Fusarium graminearum by 56.0%, 24.5%, and 43.8%, respectively, exhibiting superior performance compared to nine other bioactive NPs such as ZnO and TiO2. Importantly, MgO NPs showed an additive effect with carbendazim and azoxystrobin in inhibiting F. graminearum. The extracellular toxicity of MgO NPs against F. graminearum was mainly attributed to the inhibition of fungal growth and germination by oxidative damage, alkaline damage, and cell structure damage. Although MgO NPs could not be absorbed into mycelia, they (EC90) decreased the soluble protein content and DNA concentration of mycelia by 27.8% and 42.3%, respectively, and increased the pyruvate content by 67.4%, demonstrating that the intracellular toxicity was mainly based on their inhibition of protein and DNA production and promotion of carbohydrate degradation. With low risks to nontarget organisms, MgO NPs could be a promising nanopartner for fungicides to protect wheat from FHB and mitigate fungicide overuse.

Recent advances of copper-based metal phenolic networks in biomedical applications

Metal-phenolic Networks (MPNs) are a novel class of nanomaterial developed gradually in recent years which are self-assembled by metal ions and polyphenolic ligands. Due to their environmental protection, good adhesion, and biocompatibility with green phenolic ligands, MPNs can be used as a new type of nanomaterial. They show excellent properties such as anti-inflammatory, antioxidant, antibacterial, and anticancer, and have been widely studied in the biomedical field. As one of the most common subclasses of the MPNs family, copper-based MPNs have been widely studied for drug delivery, Photodynamic Therapy (PDT), Chemo dynamic Therapy (CDT), antibacterial and anti-inflammatory, bone tissue regeneration, skin regeneration wound repair, and metal ion imaging. In this paper, the preparation strategies of different types of copper-based MPNs are reviewed. Then, the application status of copper-based MPNs in the biomedical field under different polyphenol ligands is introduced in detail. Finally, the existing problems and challenges of copper-based MPNs are discussed, as well as their future application prospects in the biomedical field.

Emerging nanomaterials for novel wound dressings: From metallic nanoparticles and MXene nanosheets to metal-organic frameworks

The growing need for developing reliable and efficient wound dressings has led to recent progress in designing novel materials and formulations for different kinds of wounds caused by traumas, burns, surgeries, and diabetes. In cases of extreme urgency, accelerating wound recovery is of high importance to prevent persistent infection and biofilm formation. The application of nanotechnology in this domain resulted in the creation of distinct nanoplatforms for highly advanced wound-healing therapeutic approaches. Recently developed nanomaterials have been used as antibacterial agents or drug carriers to control wound infection. In the present review, the authors aim to review the recently published research on the effects of incorporating emerging nanomaterials into novel wound dressings and investigate their distinct roles in the wound healing process. It was determined that the metallic nanoparticles (NPs) exhibit antimicrobial and regenerative properties, metal oxide NPs regulate inflammation and promote tissue regeneration, MXene NPs enhance cell adhesion and proliferation, while metal-organic frameworks (MOFs) offer controlled drug delivery capabilities. Further research is required to fully understand the mechanisms and optimize the applications of these NPs in wound healing.

Advancing diabetic wound care: The role of copper-containing hydrogels

Diabetic wounds pose a significant challenge in healthcare due to their complex nature and the difficulties they present in treatment and healing. Impaired healing processes in individuals with diabetes can lead to complications and prolonged recovery times. However, recent advancements in wound healing provide reasons for optimism. Researchers are actively developing innovative strategies and therapies specifically tailored to address the unique challenges of diabetic wounds. One focus area is biomimetic hydrogel scaffolds that mimic the natural extracellular matrix, promoting angiogenesis, collagen deposition, and the healing process while also reducing infection risk. Copper nanoparticles and copper compounds incorporated into hydrogels release copper ions with antimicrobial, anti-inflammatory, and angiogenic properties. Copper reduces infection risk, modulates inflammatory response, and promotes tissue regeneration through cell adhesion, proliferation, and differentiation. Utilizing copper nanoparticles has transformative potential for expediting diabetic wound healing and improving patient outcomes while enhancing overall well-being by preventing severe complications associated with untreated wounds. It is crucial to write a review highlighting the importance of investigating the use of copper nanoparticles and compounds in diabetic wound healing and tissue engineering. These groundbreaking strategies hold the potential to transform the treatment of diabetic wounds, accelerating the healing process and enhancing patient outcomes.

Biocompatible chitin-based Janus hydrogel membranes for periodontal repair

Periodontal defects caused by severe periodontitis are a widespread issue globally. Guided tissue regeneration (GTR) using barrier membranes for alveolar bone repair is a common clinical treatment. However, most commercially available collagen barrier membranes are expensive and lack the antibacterial properties essential for effective bone regeneration. Herein, we report a natural polysaccharide chitin hydrogel barrier membrane with a Janus structure (ChT-PDA-p-HAP), featuring high antibacterial and protein-repelling activity on the outer side and good osteogenesis ability on the inner side. This multifunctional membrane is fabricated though a three-step process: (i) dissolution and regeneration of chitin, (ii) co-deposition with polydopamine (PDA) and poly(sulfobetaine methacrylate) (pSBMA), and (iii) coating with gelatin-hydroxyapatite (gelatin-HAP). In vitro cell experiments demonstrated the membrane's high biocompatibility and significant osteogenic activity. In vivo implantation in rats with periodontal defects revealed that the cemento-enamel junction index of the ChT-PDA-p-HAP membrane (1.165 mm) was superior to that of the commercial Bio-Gide® membrane (1.350 mm). This work presents a method for fabricating a chitin-based Janus barrier membrane, potentially expanding the use of chitin in tissue engineering. STATEMENT OF SIGNIFICANCE: This study introduces a Janus hydrogel membrane based on chitin, tailored for guided tissue regeneration in periodontal defects. By combining antibacterial properties and osteogenic capabilities in a single membrane, the ChT-PDA-p-HAP membrane represents a significant advancement over traditional collagen barriers. Its outer surface, enhanced by Cu2+ and PDA-pSBMA coatings, resists bacterial colonization and protein adhesion effectively, while the inner side, coated with gelatin-HAP, promotes robust bone formation. In vitro experiments demonstrate high biocompatibility and substantial osteogenic differentiation, while in vivo testing in rat models confirms good therapeutic efficacy compared to commercial membranes. This multifunctional approach not only utilizes chitin's abundant natural resource but also integrates simple coating techniques to enhance therapeutic outcomes in periodontal tissue engineering, offering promising avenues for broader biomedical applications.

Exploring Through-Space Charge Transfer-Mediated Optoelectrochemical Properties of Dual-State Luminescent Aliphatic Polymers and Optoelectronic Responses toward Metal Ions

Herein, natural-synthetic hybrid dual-state luminescent conducting polymers (DLCPs/DLCP1-DLCP8) possessing significant optoelectrochemical properties are strategically developed by the polymerization of prop-2-enamide, cis-butenedioic acid, 2-acrylamido-2-methylpropane-1-sulfonic acid, and in situ-generated 2-(3-acrylamidopropanamido)-2-methylpropane-1-sulfonic acid alongside the grafting of gum tragacanth. The spectroscopic data of aliphatic DLCPs affirm DLCP7 as the most stable supramolecular assembly endowing optoelectronic properties. Computational calculations identified -C(═O)NH-, -C(═O)OH, -OH, and -SO3H as subluminophores. The absorption spectra, excitation wavelength-/solvent-polarity-/concentration-dependent luminescence, solid state luminescence, aggregation-induced enhanced luminescence, and time-correlated single photon count (TCSPC) studies confirm the occurrence of aggregation-mediated intramolecular through-space charge transfer (ITSCT) in the excited state of DLCP7. Mulliken charge, natural bond orbital, dipole moments, and electronic potential surface analyses confirm the charge donor-acceptor system in DLCP7. Furthermore, the selective optoelectronic response of DLCP7 toward Ca2+/Cu(II) at 438/574 nm is explored using ultraviolet-visible spectra, TCSPC analyses, a dynamic light scattering study, and computational investigations. The chelation-enhanced luminescence and ITSCT inhibition are responsible for turn-on and turn-off detections of Ca2+ and Cu(II), respectively. Cu(II) → Cu(I) reduction in a DLCP7 solution is inferred from electrochemical and spectroscopic analyses. The conductivities of 9.65 × 10-5 S cm-1 (solid state) and 44.35 × 10-5 S cm-1 (solution) in DLCP7 are validated by current-voltage and electrochemical impedance measurements. Again, strong electronic conductivities of 43.89 × 10-5 S cm-1 (solid state)/53.34 × 10-5 S cm-1 (solution) and 45.42 × 10-5 S cm-1 (solid state)/64.81 × 10-5 S cm-1 (solution) are observed in Ca2+-DLCP7 and Cu(II)-DLCP7, respectively.

Nanomedicines as a cutting-edge solution to combat antimicrobial resistance

Antimicrobial resistance (AMR) poses a critical threat to global public health, necessitating the development of novel strategies. AMR occurs when bacteria, viruses, fungi, and parasites evolve to resist antimicrobial drugs, making infections difficult to treat and increasing the risk of disease spread, severe illness, and death. Over 70% of infection-causing microorganisms are estimated to be resistant to one or several antimicrobial drugs. AMR mechanisms include efflux pumps, target modifications (e.g., mutations in penicillin-binding proteins (PBPs), ribosomal subunits, or DNA gyrase), drug hydrolysis by enzymes (e.g., β-lactamase), and membrane alterations that reduce the antibiotic's binding affinity and entry. Microbes also resist antimicrobials through peptidoglycan precursor modification, ribosomal subunit methylation, and alterations in metabolic enzymes. Rapid development of new strategies is essential to curb the spread of AMR and microbial infections. Nanomedicines, with their small size and unique physicochemical properties, offer a promising solution by overcoming drug resistance mechanisms such as reduced drug uptake, increased efflux, biofilm formation, and intracellular bacterial persistence. They enhance the therapeutic efficacy of antimicrobial agents, reduce toxicity, and tackle microbial resistance effectively. Various nanomaterials, including polymeric-based, lipid-based, metal nanoparticles, carbohydrate-derived, nucleic acid-based, and hydrogels, provide efficient solutions for AMR. This review addresses the epidemiology of microbial resistance, outlines key resistance mechanisms, and explores how nanomedicines overcome these barriers. In conclusion, nanomaterials represent a versatile and powerful approach to combating the current antimicrobial crisis.

Chitosan-Copper Hybrid Nanoflowers: A Novel Nanopesticide for Controlling Rhizoctonia solani Infection in Crops

Copper-based nanomaterials are effective alternatives to traditional pesticides due to their antibacterial properties. However, the high cost and low dispersity limit their application. In this study, we synthesized cost-effective, eco-friendly, and stable chitosan-copper hybrid nanoflowers (CS-Cu HNFs) through facile self-assembly to manage agricultural diseases caused by the fungal pathogen (Rhizoctonia solani). The results show that CS-Cu HNFs, which utilized chitosan and copper phosphate as primary scaffolds, were formed via a series of nucleation, aggregation, self-assembly, and anisotropic growth processes. 200 mg/L CS-Cu HNFs exhibited an excellent inhibitory effect on R. solani, which was 6.11 times that of CuO nanoparticles, despite CS-Cu HNFs containing only 45% of Cu as that in CuO nanoparticles. Additionally, CS-Cu HNFs significantly reduced R. solani infection in various crops and displayed broad-spectrum antibacterial activity. This research provides new insights into the preparation and application of organic-inorganic hybrid nanoflowers as nanopesticides.

Copper nanoparticles incorporated visible light-curing chitosan-based hydrogel membrane for enhancement of bone repair

Alveolar bone defects caused by tumor, trauma and inflammation can lead to the loss of oral function and complicate denture restoration. Currently, guided bone regeneration (GBR) barrier membranes for repairing bone defect cannot effectively promote bone regeneration due to their unstable degradation rate and poor antibacterial properties. Furthermore, they require additional tailoring before implantation. Therefore, this study developed a visible light-curing hydrogel membrane (CF-Cu) comprising methacrylated carboxymethyl chitosan (CMCS-MA), silk fibroin (SF), and copper nanoparticles (Cu NPs) to address these shortcomings of commercial membranes. The CF-Cu hydrogel, characterized by scanning electron microscopy (SEM), a universal testing machine, and swelling and degradation tests, demonstrated a smooth porous network structure, suitable swelling ratio, biodegradability, and enhanced mechanical strength. Cytotoxicity and hemolysis tests in vitro demonstrated excellent cyto- and hemo-compatibility of the CF-Cu hydrogel extracts. Additionally, evaluation of antibacterial properties in vitro, including colony forming unit (CFU) counts, MTT assays, and live/dead fluorescence staining, showed that the CF-Cu hydrogel exhibited excellent antibacterial properties, inhibiting over 80% of S. aureus, S. mutans, and P. gingivalis with CF-1Cu hydrogel compared to the control group. Moreover, evaluation of osteogenic differentiation of rBMSCs in vitro suggested that the CF-1Cu hydrogel significantly improved alkaline phosphatase (ALP) activity and the mineralization of extracellular matrix, up-regulating the expressions of osteogenesis-related genes (Runx2, ALP, Col-1, OPN and BSP). In summary, these results indicated that CF-1Cu hydrogel exhibited excellent cytocompatibility, antibacterial and osteogenic properties in vitro. Therefore, the CF-1Cu hydrogel holds potential as a viable material for application in GBR procedures aimed at addressing bone defects.

Glycyrrhizin functionalized CuS Nanoprobes for NIR Light-based therapeutic mitigation of acne vulgaris

Acne Vulgaris or Acne is a multifactorial bacterial infection caused by Propionibacterium acne, leading to inflammation and decreased quality of life, especially in adolescence. Currently, antibiotics and retinoids are preferred for treating acne. However, their continuous usage may lead to anti-microbial resistance and other side effects. Therefore, research on developing effective strategies to reduce antimicrobial resistance and improve acne healing is ongoing. The current work reports the synthesis and evaluation of near-infrared light-absorbing copper sulfide (CuS) nanoparticles loaded with a biomolecule, Glycyrrhizin (Ga). The photothermal efficacy studies, and in-vitro and in-vivo experiments indicated that the Ga-CuS NPs generated localized hyperthermia in acne-causing bacteria, leading to their complete growth inhibition. The results indicated that the Ga-Cus NPs possess excellent antibacterial and anti-inflammatory properties in the acne and inflammatory models. This could be from the synergistic effect of CuS NPs mediated mild Photothermal effect and inherent pharmacological properties of Ga. Further detailed studies of the formulations can pave the way for application in cosmetic clinics for the effective and minimally invasive management of Acne-like conditions.

An insight into impact of nanomaterials toxicity on human health

In recent years, advances in nanotechnology have significantly influenced electronics manufacturing, industrial processes, and medical research. Various industries have seen a surge in the use of nanomaterials. However, several researchers have raised the alarm about the toxicological nature of nanomaterials, which appear to be quite different from their crude forms. This altered nature can be attributed to their unique physicochemical profile. They can adversely affect human health and the environment. Nanomaterials that have been released into the environment tend to accumulate over time and can cause a significant impact on the ecosystem and organisms with adverse health effects. Increased use of nanoparticles has led to increased human exposure in their daily lives, making them more vulnerable to nanoparticle toxicity. Because of their small size, nanomaterials can readily cross biological membranes and enter cells, tissues, and organs. Therefore, the effect of nanomaterials on the human environment is of particular concern. The toxicological effects of nanomaterials and their mechanisms of action are being researched worldwide. Technological advances also support monitoring new nanomaterials marketed for industrial and household purposes. It is a challenging area because of the exceptional physicochemical properties of nanomaterials. This updated review focuses on the diverse toxicological perspective of nanomaterials. We have discussed the use of different types of nanoparticles and their physiochemical properties responsible for toxicity, routes of exposure, bio-distribution, and mechanism of toxicity. The review also includes various in vivo and in vitro methods of assessing the toxicity of nanomaterials. Finally, this review will provide a detailed insight into nano material-induced toxicological response, which can be beneficial in designing safe and effective nanoparticles.

Dual Antibacterial Properties of Copper-Coated Nanotextured Stainless Steel

Bacterial adhesion to stainless steel, an alloy commonly used in shared settings, numerous medical devices, and food and beverage sectors, can give rise to serious infections, ultimately leading to morbidity, mortality, and significant healthcare expenses. In this study, Cu-coated nanotextured stainless steel (nSS) fabrication have been demonstrated using electrochemical technique and its potential as an antibiotic-free biocidal surface against Gram-positive and negative bacteria. As nanotexture and Cu combine for dual methods of killing, this material should not contribute to drug-resistant bacteria as antibiotic use does. This approach involves applying a Cu coating on nanotextured stainless steel, resulting in an antibacterial activity within 30 min. Comprehensive characterization of the surface revealing that the Cu coating consists of metallic Cu and oxidized states (Cu2+ and Cu+), has been performed by this study. Cu-coated nSS induces a remarkable reduction of 97% in Gram-negative Escherichia coli and 99% Gram-positive Staphylococcus epidermidis bacteria. This material has potential to be used to create effective, scalable, and sustainable solutions to prevent bacterial infections caused by surface contamination without contributing to antibiotic resistance.

Unexpectedly high antibacterial ability of water in copper pot with tiny amount of plant leaves

Water disinfection by copper vessels has been prevalent over thousands of years. Unfortunately, people are still suffering from the bacterial pollution in drinking water. Here we show that, only through steeping with tiny amounts of common plant leaves, the room-temperature water in copper pots has unexpectedly high antibacterial ability. Remarkably, copper ions released from copper pots into water are in concentrations lower than the WHO safety threshold for drinking water, and have effective antibacterial ability when water contains specific leave components (polyphenols and/or lignin). Our computations show that the key to enhance antibacterial ability is the great increase in the proportion of Cu+ induced by aromatic rings in these leave components, which has been demonstrated by our experiments. The findings may disclose the mystery of copper vessels for water disinfection, and more importantly, provide effective antibacterial applications in industries and daily lives, by safely using copper ions together with biocompatible natural substances.

The impact of copper nanoparticles surfactant on the structural and biological properties of chitosan/sodium alginate wound dressings

Multifunctional wound dressings based on hydrogels are an efficacious and practicable strategy in therapeutic processes and accelerated chronic wound healing. Here, copper (Cu) nanoparticles were added to chitosan/sodium alginate (CS/SA) hydrogels to improve the antibacterial properties of the prepared wound dressings. Due to the super-hydrophobicity of Cu nanoparticles, polyethylene glycol (PEG) was used as a surfactant, and then added to the CS/SA-based hydrogels. The CS/SA/Cu hydrogels were synthesized with 0, 2, 3.5, and 5 wt% Cu nanoparticles. The structural and morphological properties in presence of PEG were evaluated using Fourier-transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), and field emission scanning electron microscopy (FESEM). The biodegradation and swelling properties of the hydrogels were investigated in phosphate buffer saline (PBS) at 37 °C for up to 30 days. Cell viability and adhesion, as well as antibacterial behavior, were investigated via MTT assay, FESEM, and disk diffusion method, respectively. The obtained results showed that PEG provided new intra- and intermolecular bonds that affected significantly the hydrogels' degradation and swelling ratio, which increased up to ~1200 %. Cell viability reached ~110 % and all samples showed remarkable antibacterial behavior when CS/SA/Cu containing 2 wt% was introduced. This study provided new insights regarding the use of PEG as a surfactant for Cu nanoparticles in CS/SA hydrogel wound dressing, ultimately affecting the chemical bonding and various properties of the prepared hydrogels.

Recovery of copper/carbon matrix nanoheteroarchitectures from recyclable electronic waste and their efficacy as antibacterial agents

Innovative solutions are urgently needed with the growing environmental hazard of electronic waste (e-waste) and the rising global threat of bacterial infections. This study addresses both issues by using e-waste to produce copper nanoparticles within a carbon matrix (Cu/C NPs), mitigating environmental hazards while exploring their antibacterial properties. Printed circuit boards from discarded computers were collected and treated with 2 M ammonium citrate dissolved in 8% ammonia solution. The leached solution was used to synthesize copper particles using ascorbic acid. The synthesized Cu/C NPs were characterized using various techniques such as EDX, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. The antibacterial activity of Cu/C NPs against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was evaluated using colony-forming unit (CFU) reduction assay and calculating the minimum inhibitory concentrations (MICs). The Cu/C NPs were found to be effective against E. coli and S. aureus with 100% and 98% CFU reduction, respectively, with MICs ranging from 250 to 375 μg mL-1 for E. coli and 375 to 750 μg mL-1 for S. aureus, according to the bacterial load. The bactericidal kinetics showed complete bacterial elimination after 5 and 7 hours for E. coli and S. aureus, respectively. This study presents a sustainable approach for utilizing e-waste and demonstrates the potential of the recovered nanoparticles for antibacterial applications.

From agro-food waste to nanoparticles: green synthesis of copper nanoparticles with lignin peroxidase enzyme produced by Anoxybacillus rupiensis using peanut shells

This study presents a novel approach for the eco-friendly green synthesis of copper nanoparticles (Cu NPs) using enzymatic mediation which is an environmentally benign alternative to conventional methods, offering control over particle size and shape. Anoxybacillus rupiensis BS1 thermophilic bacterium was isolated from Erzurum's Pasinler hot spring and lignin peroxidase enzyme production conditions (incubation time 96 h, 40 g/L shell amount, pH 8.5, 150 rpm, and 60 °C temperature) were used in the production of peroxidase enzyme using peanut waste which has been optimized. The characterization of the synthesized Cu NPs was performed using various analytical techniques, including UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), confirming the successful production of stable and well-defined nanoparticles. Furthermore, the biological activities of the synthesized Cu NPs were explored, revealing their potential for antimicrobial applications. The antibacterial efficacy of the Cu NPs against some pathogens such as Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, and Bacillus cereus was examined. It was determined that Cu NPs were effective on all pathogens and had the highest effectiveness against the S. pyogenes pathogen (19.0 mm). This study not only presents an innovative and sustainable approach for the synthesis of Cu NPs but also highlights the multifaceted biological activities of these nanoparticles, opening avenues for diverse applications in the fields of medicine, agriculture, and environmental remediation. The utilization of peanut shell wastes as a substrate for enzyme production adds value to agricultural by-products, contributing to the development of a circular and sustainable economy.

Efficient Self-cleaning and antibacterial ceramics with active sites fully exposed obtained from rare earth waste

The utilization of rare earth polishing powder waste (RPW) to prepare antibacterial ceramics can effectively avoid problems of pollution in the recycling process and waste of rare earth resources. Herein, a novel RPW-based antibacterial ceramics was developed, which possesses the core-shell structure with ceramics as the cores and the CeO2/BiOCl as the superficial coating. The antibacterial ceramics display notable antibacterial activity, and the inactivation rates of 3.3 log under visible light irradiation in 30 min and 2.4 log under darkness in 1 h were achieved, and the zone of inhibition values was found to be 16.6 mm for E.coil. The hardness of antibacterial ceramics was measured to be 897 (±38) HV, higher than commercial porcelain's hardness (600 HV). The antibacterial mechanism was verified by the Ce ion release, reactive species, and fluorescence-based live/dead cells. This study presents a novel antibacterial ceramic structure and green economic reuse method of rare earth waste.

Novel Biomaterials for Wound Healing and Tissue Regeneration

Skin is the first defense barrier of the human body, which can resist the invasion of external dust, microorganisms and other pollutants, and ensure that the human body maintains the homeostasis of the internal environment. Once the skin is damaged, the health threat to the human body will increase. Wound repair and the human internal environment are a dynamic process. How to effectively accelerate the healing of wounds without affecting the internal environment of the human body and guarantee that the repaired tissue retains its original function as much as possible has become a research hotspot. With the advancement of technology, researchers have combined new technologies to develop and prepare various types of materials for wound healing. This article will introduce the wound repair materials developed and prepared in recent years from three types: nanofibers, composite hydrogels, and other new materials. The paper aims to provide reference for researchers in related fields to develop and prepare multifunctional materials. This may be helpful to design more ideal materials for clinical application, and then achieve better wound healing and regeneration effects.

Multidentate polyoxometalate modification of metal nanoparticles with tunable electronic states

To respond to the increasing demands for practical applications, stabilization and property modulation of metal nanoparticles have emerged as a key research subject. Herein, we present a viable protocol for preparing small metal nanoparticles (<5 nm; Ag, Pd, Pt, and Ru) via multidentate polyoxometalate (POM, [SiW9O34]10-) modification. In addition to enhancing stability, the POMs can modulate the electronic states of metal nanoparticles. Moreover, immobilization of the POM-modified metal nanoparticles on solid supports enables further tuning of the electronic states via a cooperative effect between the POMs and the supports without altering the particle size. Notably, POM-modified Pd nanoparticles on carbon support exhibited superior catalytic activity and selectivity in hydrogenation reactions in comparison with the catalyst without the POM modification.

Research and Application of Chitosan Nanoparticles in Orthopedic Infections

Orthopedic infection is one of the most intractable orthopedic problems. Bacteria resistant to antibiotics also develop gradually. Chitosan is widely used in the Biomedical field because of its high biocompatibility, biodegradability, and antibacterial activity. Chitosan-based drug delivery systems are frequently utilized to produce controlled medication release. When combined with antibiotics, synergistic antibacterial effects can be achieved. Chitosan-based nanoparticles are one of the most widely used applications in drug delivery systems. The focus of this review is to provide information on new methods being developed for chitosan-based nanoparticles in the field of bone infection treatment, including chitosan nanoparticles for antibacterial purposes, Ch-loaded with antibiotics, Ch-loaded with metal, and used as immune adjuvants. It may Provide ideas for the fundamental research and the prospects of future clinical applications of orthopedic infections.

Nitroreductase-responsive nanoparticles for in situ fluorescence imaging and synergistic antibacterial therapy of bacterial keratitis

As bacterial keratitis progresses rapidly, prompt intervention is necessary. Current diagnostic processes are time-consuming and invasive, leading to improper antibiotics for treatment. Therefore, innovative strategies for diagnosing and treating bacterial keratitis are urgently needed. In this study, Cu2-xSe@BSA@NTRP nanoparticles were developed by loading nitroreductase-responsive probes (NTRPs) onto Cu2-xSe@BSA. These nanoparticles exhibited integrated fluorescence imaging and antibacterial capabilities. In vitro and in vivo experiments showed that the nanoparticles produced responsive fluorescence signals in bacteria within 30 min due to an interaction between the released NTRP and bacterial endogenous nitroreductase (NTR). When combined with low-temperature photothermal therapy (PTT), the nanoparticles effectively eliminated E. coli and S. aureus, achieved antibacterial efficacy above 95% and facilitated the re-epithelialization process at the corneal wound site in vivo. Overall, the Cu2-xSe@BSA@NTRP nanoparticles demonstrated potential for rapid, noninvasive in situ diagnosis, treatment, and visualization assessment of therapy effectiveness in bacterial keratitis.

Molybdenum Disulfide-Supported Cuprous Oxide Nanocomposite for Near-Infrared-I Light-Responsive Synergistic Antibacterial Therapy

Drug-resistant bacterial infections pose a serious threat to human health; thus, there is an increasingly growing demand for nonantibiotic strategies to overcome drug resistance in bacterial infections. Mild photothermal therapy (PTT), as an attractive antibacterial strategy, shows great potential application due to its good biocompatibility and ability to circumvent drug resistance. However, its efficiency is limited by the heat resistance of bacteria. Herein, Cu2O@MoS2, a nanocomposite, was constructed by the in situ growth of Cu2O nanoparticles (NPs) on the surface of MoS2 nanosheets, which provided a controllable photothermal therapeutic effect of MoS2 and the intrinsic catalytic properties of Cu2O NPs, achieving a synergistic effect to eradicate multidrug-resistant bacteria. Transcriptome sequencing (RNA-seq) results revealed that the antibacterial process was related to disrupting the membrane transport system, phosphorelay signal transduction system, oxidative stress response system, as well as the heat response system. Animal experiments indicated that Cu2O@MoS2 could effectively treat wounds infected with methicillin-resistant Staphylococcus aureus. In addition, satisfactory biocompatibility made Cu2O@MoS2 a promising antibacterial agent. Overall, our results highlight the Cu2O@MoS2 nanocomposite as a promising solution to combating resistant bacteria without inducing the evolution of antimicrobial resistance.

Biochemical Behavior, Influence on Cell DNA Condition, and Microbiological Properties of Wool and Wool-Copper Materials

The paper presents the study concerning the preparation and physio-chemical and biological properties of wool-copper (WO-Cu) materials obtained by the sputter deposition of copper onto the wool fibers. The WO-Cu material was subjected to physio-chemical and biological investigations. The physio-chemical investigations included the elemental analysis of materials (C, N, O, S, and Cu), their microscopic analysis, and surface properties analysis (specific surface area and total pore volume). The biological investigations consisted of the antimicrobial activity tests of the WO-Cu materials against colonies of Gram-positive (Staphylococcus aureus) bacteria, Gram-negative (Escherichia coli) bacteria, and fungal mold species (Chaetomium globosum). Biochemical-hematological tests included the evaluation of the activated partial thromboplastin time and pro-thrombin time. The tested wool-copper demonstrated the ability to interact with the DNA in a time-dependent manner. These interactions led to the DNA's breaking and degradation. The antimicrobial and antifungal activities of the WO-Cu materials suggest a potential application as an antibacterial/antifungal material. Wool-copper materials may be also used as customized materials where the blood coagulation process could be well controlled through the appropriate copper content.

Highly Crystalline Copper Aluminum-Layered Double Hydroxides with Intrinsic Fenton-Like Catalytic Activity for Robust Oral Health Management

As the main challenge of dental healthcare, oral infectious diseases are highly associated with the colonization of pathogenic microbes. However, current antibacterial treatments in the field of stomatology still lack a facile, safe, and universal approach. Herein, we report the controllable synthesis of copper aluminum-layered double hydroxides (CuAl-LDHs) with high Fenton-like catalytic activity, which can be utilized in the treatment of oral infectious diseases with negligible side effects. Our strategy can efficiently avoid the unwanted doping of other divalent metal ions in the synthesis of Cu-contained LDHs and result in the formation of binary CuAl-LDHs with high crystallinity and purity. Evidenced by experimental and theoretical results, CuAl-LDHs exhibit excellent catalytic ability toward the ·OH generation in the presence of H2O2 and hold strong affinity toward bacteria, endowing them with great catalytic sterilization against both Gram-positive and Gram-negative bacteria. As expected, these CuAl-LDHs provide outstanding treatments for mucosal infection and periodontitis by promoting wound healing and remodeling of the periodontal microenvironment. Moreover, toxicity investigation demonstrates the overall safety. Accordingly, the current study not only provides a convenient and economic strategy for treating oral infectious diseases but also extends the development of novel LDH-based Fenton or Fenton-like antibacterial reagents for further biomedical applications.

Utilizing Copper Nanoclusters as a Fluorescent Probe for Quantitative Monitoring of Doxorubicin Anticancer Drug

Monitoring the amount of chemotherapeutic drugs in biological fluids is extremely important for dose adjustment or control of side effects during the treatment process. In this study, copper nanoclusters (Cu NCs) were synthesized via a one-pot method using ammonium citrate as the reducing agent. Cu NCs exhibited bright blue fluorescence, good optical properties and outstanding photostability. The produced Cu NCs were characterized in detail by UV‒vis absorption, fluorescence spectroscopy and transmission electron microscopy (TEM). The produced Cu NCs showed a high quantum yield of 0.97. A fluorescence system was used for doxorubicin (DOX) determination using Cu NCs as a nanoprobe. The presence of DOX decreased the fluorescence intensity of the CuNCs at 445 nm but increased the fluorescence intensity of the CuNCs at 619 nm. As a result, quantitative detection of DOX can be achieved by measuring the ratio of fluorescence intensities at 445 and 619 nm (F619/F445). The fluorescence quenching activity of the Cu NCs was determined to have a linear relationship with the amount of DOX anticancer drug in the range of 1-15 ppb, and the usability of the Cu NCs as a sensor for detection in biological fluids was demonstrated. It was determined that this method can be used to measure the amount of DOX in biological samples effectively.

Metal-polyphenol coordination nanosheets with synergistic peroxidase-like and photothermal properties for efficient antibacterial treatment

Bacterial infections pose a serious threat to human health and socioeconomics worldwide. In the post-antibiotic era, the development of novel antimicrobial agents remains a challenge. Polyphenols are natural compounds with a variety of biological activities such as intrinsic antimicrobial activity and antioxidant properties. Metal-polyphenol obtained by chelation of polyphenol ligands with metal ions not only possesses efficient antimicrobial activity but also excellent biocompatibility, which has great potential for application in biomedical and food packaging fields. Herein, we developed metal-polyphenol coordination nanosheets named copper oxidized tannic acid quinone (CuTAQ) possessing efficient antibacterial and anti-biofilm effects, which was synthesized by a facile one-pot method. The synthesis was achieved by chelation of partially oxidized tannic acid (TA) with Cu2+ under mild conditions, which supports low-cost and large-scale production. It was demonstrated that CuTAQ exhibited high antibacterial activity via disrupting the integrity of bacterial cell membranes, inducing oxidative stress, and interfering with metabolism. In addition, CuTAQ exhibits excellent peroxidase catalytic activity and photothermal conversion properties, which play a significant role in enhancing its bactericidal and biofilm scavenging abilities. This study provides insights for rational design of innovative metal-polyphenol nanomaterials with efficient antimicrobial properties.

In situ forming Hydrogel with adding ZnO Nano-particle for effectively methicillin-resistant Staphylococcus aureus infected frostbite injury

Hydrogel has emerged as a promising wound dressing material, and in situ forming hydrogel has emerged as a promising wound dressing recently. But most in situ forming hydrogel are normally unstable. Herein, we report an in-situ forming hydrogel synthesized from poly(Nisopropylacrylamide166-co-n-butyl acrylate9)-poly(ethyleneglycol)-poly(N-isopropylacrylamide166-co-n-butyl acrylate9) copolymer (P(NIPAM166-co-nBA9)-PEG-P(NIPAM166-conBA9), denoted as PEP) and zinc oxide nano-particle(ZnO nano-particle) in response to skin temperature. This thermoresponsive hydrogel exhibits sol-gel reversibility at high temperatures, which is closed to the temperature of human skin. To investigate its healing effects, we used the Hydrogel dressing® in an SD rat model. The biocompatibility and antibacterial ability against methicillin-resistant Staphylococcus aureus(MRSA) of this PEP-ZnO hydrogel wound dressing are confirmed in vitro and in vivo, which could transparently promote the healing of a MRSA-infected frostbitten skin Injury.

Materials and methods

Thirty rats were randomly divided into two groups. The treatment group received hydrogel and transparent film dressing 30 min to 1 h post-burn, while the control group received only cotton dressing. The wound area was measured, and the wound closure rate was calculated on days 3, 7, and 14 post-surgery. Tissue samples were collected from each rat on these days and stored at -80 °C for histological analysis using H&E, Masson and immunohistochemical staining. This analysis assessed factors such as granulation tissue length, re-epithelialization, re-angiogenesis, collagen deposition, inflammatory cell infiltration, and collagen production. Clinical and histological assessments at 14 days showed more rapid healing in the hydrogel dressing group compared to the control group.

Conclusion

Our results indicate that the design of our hydrogel for cooling injury wounds effectively improves healing and mitigates the damage from low temperatures.

Dual-mode harvest solar energy for photothermal Cu2-xSe biomineralization and seawater desalination by biotic-abiotic hybrid

Biotic-abiotic hybrid photocatalytic system is an innovative strategy to capture solar energy. Diversifying solar energy conversion products and balancing photoelectron generation and transduction are critical to unravel the potential of hybrid photocatalysis. Here, we harvest solar energy in a dual mode for Cu2-xSe nanoparticles biomineralization and seawater desalination by integrating the merits of Shewanella oneidensis MR-1 and biogenic nanoparticles. Photoelectrons generated by extracellular Se0 nanoparticles power Cu2-xSe synthesis through two pathways that either cross the outer membrane to activate periplasmic Cu(II) reduction or are directly delivered into the extracellular space for Cu(I) evolution. Meanwhile, photoelectrons drive periplasmic Cu(II) reduction by reversing MtrABC complexes in S. oneidensis. Moreover, the unique photothermal feature of the as-prepared Cu2-xSe nanoparticles, the natural hydrophilicity, and the linking properties of bacterium offer a convenient way to tailor photothermal membranes for solar water production. This study provides a paradigm for balancing the source and sink of photoelectrons and diversifying solar energy conversion products in biotic-abiotic hybrid platforms.

Biosynthesis, characterization, and anticoagulant properties of copper nanoparticles from red seaweed of Acanthophora sp

INTRODUCTION

In the last few decades, nanoparticles have found extensive use in a variety of biological applications. Traditional medicine widely uses Acanthophora sp., a marine macroalgae, to cure and prevent diabetes, skin disorders, and blood clotting.

OBJECTIVE

The present study aims to investigate whether green-synthesized copper nanoparticles (CuNPs) might work as an anticoagulant.

METHODOLOGY

The CuNPs were made using an environmentally friendly method that uses Acanthophora extract. We used UV-vis spectroscopy to assess the surface plasmon resonance of the material, scanning electron microscopy (SEM) to analyze its form, and energy dispersive X-ray (EDX) spectroscopy to identify the material's constituent elements. Furthermore, Fourier-transform infrared (FT-IR) determined the functional groups of the CuNPs.

RESULTS

The biosynthesis of CuNPs was confirmed by UV-vis spectroscopy, which showed a surface plasmon resonance peak at 570 nm. The FT-IR analysis showed that certain functional groups are involved in the formation of CuNPs. These groups include OH stretching, C=O stretching, C-H bonding, C-N bonding, and Cu vibration. SEM analysis demonstrated the morphology of CuNPs synthesized, with a size of 0.5 μm, while EDS analysis confirmed their purity. The anticoagulant activity of prothrombin time (PT) and activated partial thromboplastin time (aPTT) assays showed that the clotting time got longer depending on the concentration. The CuNPs synthesized from Acanthophora had strong anticoagulant effects at 100 μg/mL, further suggesting that they might be useful as a natural blood thinner.

CONCLUSION

The interesting thing we observed is that the green-synthesized CuNPs made from Acanthophora extract could be used in anticoagulation therapy.